Destroyed DuetWifi

I had an error while setting up my printer. Through a clogged Nozzle I decided to loosely screw the Hotend and to solve the blockage. When I put the holder aside, the Hotend has slipped out of the device and swung against the IR probe. Then I immediately disconnected the electricity, but smoke was generated. Now the board is no longer available, neither via USB nor via WLAN. On the board you can not see anything, even on the IR sample is nothing to see. Can you help me?

The smoke came from the area of ​​the IR Probe, but I can not say that exactly.
There are no signs of damage on the board and the IR probe.
When I touch the SD card connector, I notice heat there.
All LEDs on the board light up when I connect it via USB.

Try with the SD card removed( and a different SD card if you have on you want to risk), that might be fried. It's possible that that is locking the board up. It's equally possible the whole board is fried

If Duet isn't visible in Device Manager that means the controller isn't working. If only SD Card is getting hot it could be it's damaged and drawing the 3.3V down - resulting the main controller not being able to operate. There is also LED on the edge showing the presence of 3.3V (next to Erase button)